It is common, and in some jurisdictions required, for businesses or other enterprises to have concrete emergency action plans and equipment, such as alarm systems and written descriptions of procedures for responding to a fire or other emergency, including evacuation procedures, procedures to be followed by employees who remain to perform critical shutdown operations before evacuating, procedures to account for employees after evacuation, and emergency route assignments. Despite having such plans and equipment in place, in practice an actual emergency event is nevertheless chaotic. For example, from day to day and hour to hour, it can be difficult to be aware of which individuals were in a facility at a time of an emergency, and which of those individuals have not yet evacuated the facility. Also, a number of unplanned situations may arise in an emergency, such as individuals who are unable to evacuate and possibly unable to notify others of their inability to evacuate. Additionally, reliance in fixed installations of alarms and sensors for alerting others to emergency situations can hinder timely and effective response to such situations.